The present invention relates to a combination check flow control and sequencing valve having a reciprocating and rotating sequencing sealing means and check flow control valve means to distribute fluid from an inlet sequentially out through a plurality of outlets, and particularly to an improved combination check flow control and sequencing disc means which will respond to very low fluid flow rates and even to near-zero-pressure conditions.
Previous sequencing valves have failed to respond to very low flow rates and could falsely cycle when fluid pressure surged at low flow conditions. Further, fluid flow would begin before the valve was fully seated causing some fluid to pass out of other than the port selected. The sequencing valve in Slagel, U.S. Pat. No. 4,034,775, realizing an increased ability to respond and sequence properly at low fluid flow rates by incorporating a cup-shaped check valve incurs similar problems at very low fluid flow rates and inlet pressure fluctuations.